Early Perturbations in Red Blood Cells in Response to Murine Malarial Parasite Infection: Proof-of-Concept (1)H NMR Metabolomic Study

Background: The major focus of metabolomics research has been confined to the readily available biofluids—urine and blood serum. However, red blood cells (RBCs) are also readily available, and may be a source of a wealth of information on vertebrates. However, the comprehensive metabolomic characterization of RBCs is minimal although they exhibit perturbations in various physiological states. RBCs act as the host of malarial parasites during the symptomatic stage. Thus, understanding the changes in RBC metabolism during infection is crucial for a better understanding of disease progression. Methods: The metabolome of normal RBCs obtained from Swiss mice was investigated using (1)H NMR spectroscopy. Several 1 and 2-dimensional (1)H NMR experiments were employed for this purpose. The information from this study was used to investigate the changes in the RBC metabolome during the early stage of infection (~1% infected RBCs) by Plasmodium bergheii ANKA. Results: We identified over 40 metabolites in RBCs. Several of these metabolites were quantitated using (1)H NMR spectroscopy. The results indicate changes in the choline/membrane components and other metabolites during the early stage of malaria. Conclusions: The paper reports the comprehensive characterization of the metabolome of mouse RBCs. Changes during the early stage of malarial infection suggest significant metabolic alteration, even at low parasite content (~1%). General significance: This study should be of use in maximizing the amount of information available from metabolomic experiments on the cellular components of blood. The technique can be directly applied to real-time investigation of infectious diseases that target RBCs.